Contrast-Induced Encephalopathy after Cerebral Angiogram: A Case Series and Review of Literature

Neuroradiological features of contrast-induced neurotoxicity: A systematic review and pooled analysis

BACKGROUND

Contrast-induced neurotoxicity (CIN), is an increasingly recognised complication of endovascular procedures, presenting as a spectrum of neurological symptoms that mimic ischaemic stroke. The diagnosis of CIN remains a clinical challenge, and stereotypical imaging findings are not established. This study was conducted to characterise the neuroimaging findings in patients with CIN, to raise diagnostic awareness and improve decision making.

METHODS

We performed a systematic review of PubMed and Embase databases from inception (1946/1947) to June 2023 for reports of CIN following administration of iodinated contrast media. Studies with a final diagnosis of CIN, which provided details of neuroimaging were included. All included cases were pooled and descriptive analysis was conducted.

RESULTS

A total of 84 patients were included, with a median age of 64 years. A large proportion of patients had normal imaging (CT 40.8 %, MRI 53.1 %). CT abnormalities included cortical/subarachnoid hyperattenuation (42.1 %), cerebral oedema/sulcal effacement (26.3 %), and loss of grey-white differentiation (7.9 %). Frequently reported MRI abnormalities included brain parenchymal MRI signal change (40.8 %) and cerebral oedema (12.2 %), most commonly observed on FLAIR sequences (26.5 %). Characterisation of imaging findings according to anatomical location and clinical symptoms has been conducted.

CONCLUSIONS

Neuroimaging is an essential part of the diagnostic workup of CIN. Analysis of the anatomical location and laterality of imaging abnormalities may suggest relationship between radiological features and actual clinical symptoms, although this remains to be confirmed with dedicated study. Radiological abnormalities, particularly CT, appear to be transient and reversible in most patients.

Acute Transient Contrast-Induced Neurologic Deficit as a Complication of Percutaneous Coronary Intervention

Acute transient contrast-induced neurologic deficit is an uncommon condition triggered by the administration of intra-arterial contrast during angiography. It can present with encephalopathy, cortical blindness, seizures, or focal deficits. This report describes a patient who presented with severe neurologic deficits after percutaneous coronary intervention, with complete symptom resolution within 72 hours.

Pathophysiology of Contrast-Induced Neurotoxicity: A Narrative Review of Possible Mechanisms

BACKGROUND

Contrast-induced neurotoxicity (CIN) is an increasingly observed event following the administration of iodinated contrast. It presents as a spectrum of neurological symptoms that closely mimic ischaemic stroke, however, CIN remains a poorly understood clinical phenomenon. An appreciation of the underlying pathophysiological mechanisms is essential to improve clinical understanding and enhance decision-making.

METHODS

A broad literature search of Medline (1946 to December 2022) and Embase (1947 to December 2022) was conducted. Articles discussing the pathophysiology of CIN were reviewed.

SUMMARY

The pathogenesis of CIN appears to be multifactorial. A key step is likely blood-brain barrier (BBB) breakdown due to factors including ischaemic stroke, uncontrolled hypertension, and possibly contrast agents themselves, among others. This is followed by passage of contrast agents across the BBB, leading to chemotoxic sequelae on neural tissue.

KEY MESSAGES

This review provides a clinically oriented review on the pathophysiology of CIN to enhance knowledge and improve decision-making among clinicians.

Contrast-Induced Encephalopathy after Endovascular Treatment: Two Case Reports

Contrast-induced encephalopathy (CIE) is a rare neurological complication that occurs after the use of contrast medium in various angiographic procedures. Symptoms can be different, from headache to severe neurological deficit and coma. In the articles published to date, symptoms appeared immediately after application of contrast agent or within 24 hours. Here we present two cases of patients in whom CIE developed delayed after endovascular treatment.

Contrast-Induced Encephalopathy: A Rare Complication in a Patient on Peritoneal Dialysis with Several Risk Factors

Major adverse renal and cardiovascular events are reported for high-risk patients undergoing intra-arterial procedures, even if performed with iso-osmolar contrast media (CM). We report a case of contrast-induced encephalopathy (CIE) in a peritoneal dialysis (PD) patient, affected by diabetes, hypertension, and chronic heart failure. A 78-year-old PD patient (diuresis 1,000 mL) underwent a percutaneous angioplasty of the carotid. Immediately after the exam, he developed mental confusion and aphasia. Encephalic computed tomography scan and magnetic resonance imaging excluded ischemia or hemorrhage, but both showed cerebral edema; EEG showed right hemisphere abnormalities, sequelae of recent ischemia. Mannitol and steroids were administered to reduce edema, and additional PD exchange was performed with depurative aim. Within 2 days the patient completely recovered. CIE mimics severe neurological diseases, and it should be considered as differential diagnosis if symptoms come out soon after intra-arterial administration of CM, especially in high-risk patients. Our patient suffered from diabetes, chronic kidney disease, hypertension, chronic heart failure, which are possible contributing factors to the development of CIE. Moreover, this clinical scenario is noteworthy because the development in a patient who underwent PD had never been described before.

Fully Reversible Contrast-Induced Encephalopathy Mimicking Stroke after Flow Diverter Treatment of Carotid Cave Aneurysm

Contrast-induced encephalopathy (CIE) is a rare complication of coronary and neurointerventional procedures. The condition is believed to arise from endothelial damage secondary to exposure to iodinated contrast media. A wide spectrum of clinical manifestations has been reported including seizures, cortical blindness, and focal neurological deficits. This report details the case of fully reversible CIE mimicking severe anterior circulation stroke in a 55-year-old female following elective endovascular treatment with a flow diverter of a carotid cave aneurysm. The patient was managed conservatively with intravenous hydration and steroids and showed an excellent prognosis with supportive management.

Contrast-Induced Encephalopathy Presenting With Fever After Coronary Angiography: A Case Report

Contrast-induced encephalopathy (CIE) is a rare complication that occurs after exposure to contrast media, and it usually manifests with transient neurological deficits that include cortical blindness, altered mental status, and paralysis. It is self-limited, and symptoms usually resolve within 48-72 hours. It requires a high index of suspicion and must be taken into consideration in every patient developing a neurological manifestation after the administration of radiocontrast media. We report a case of post-coronary angiography contrast-induced encephalopathy with low-grade fever and negative imaging.

Contrast-induced encephalopathy and nonconvulsive status epilepticus after diagnostic cerebral angiography in an end-stage renal disease patient

A 70-year-old man with a history of recurrent ischemic stroke and end-stage renal disease was admitted to the neurology department for a transient ischemic attack. The patient underwent transfemoral cerebral angiography with iopamidol to evaluate the status of carotid stenosis. On the same day, the patient developed drowsy mentality, global aphasia, and fever. Electroencephalography showed continuous regional rhythmic delta activities (0.5 to 1.0 Hz) without definite spatiotemporal evolution, suggestive of focal seizure disorder arising from the left temporal area and ictal-interictal continuum. Computed tomography perfusion images showed hyperperfusion in the left hemisphere. The patient was diagnosed with contrast-induced encephalopathy and associated nonconvulsive status epilepticus. The patient was treated with oral lacosamide, levetiracetam, and daily hemodialysis. The patient’s mental status recovered after 8 days of intensive care unit care.

Contrast‐Induced encephalopathy following diagnostic coronary angiography

Contrast‐induced encephalopathy (CIE) is a rare, reversible complication of coronary angiography that can mimic acute strokes. This case illustrates the diagnostic challenges for a patient presenting with confusion following coronary angiography and raises awareness for CIE as diagnosis of exclusion.

MAP Kinase Pathways in Brain Endothelial Cells and Crosstalk with Pericytes and Astrocytes Mediate Contrast-Induced Blood-Brain Barrier Disruption

Neurointervention with contrast media (CM) has rapidly increased, but the impact of CM extravasation and the related side effects remain controversial. This study investigated the effect of CM on blood–brain barrier (BBB) integrity. We established in vitro BBB models using primary cultures of rat BBB-related cells. To assess the effects of CM on BBB functions, we evaluated transendothelial electrical resistance, permeability, and tight junction (TJ) protein expression using immunohistochemistry (IHC) and Western blotting. To investigate the mechanism of iopamidol-induced barrier dysfunction, the role of mitogen-activated protein (MAP) kinases in brain endothelial cells was examined. We assessed the effect of conditioned medium derived from astrocytes and pericytes under iopamidol treatment. Short-term iopamidol exposure on the luminal side induced transient, while on the abluminal side caused persistent BBB dysfunction. IHC and immunoblotting revealed CM decreased the expression of TJ proteins. Iopamidol-induced barrier dysfunction was improved via the regulation of MAP kinase pathways. Conditioned medium from CM-exposed pericytes or astrocytes lacks the ability to enhance barrier function. CM may cause BBB dysfunction. MAP kinase pathways in brain endothelial cells and the interactions of astrocytes and pericytes mediate iopamidol-induced barrier dysfunction. CM extravasation may have negative effects on clinical outcomes in patients.